The structures prepared by high temperature–pressure treatment of Cz-Si heavily implanted with He +

Abstract

Structure of Czochralski grown silicon heavily implanted with He + (dose 1 × 10 17 cm −2, energy 150 keV) and processed at up 1400 K under enhanced hydrostatic pressure (HP, up to 1.1 GPa) for up to 10 h was studied by X-ray diffuse scattering and photoluminescence measurements. Enhanced pressure affects the microstructure of Si:He; the type and concentration of defects in Si:He are dependent on processing parameters. In particular, HP affects the creation of dislocations, especially for the treatments at 920–1270 K. The retarded helium out-diffusion under HP is responsible in part for the effects observed. Calculations based on the density functional theory confirm that the formation energy of vacancies in Si is reduced by the presence of He and by enhanced pressure.